Rapid determination of polarity sense by an energy‐dispersive diffractometer

The polarity sense of the non‐centrosymmetric GaP crystal has rapidly been determined by use of an energy‐dispersive diffractometer by choosing a suitable scattering angle, where the anomalous scattering is heavy, for example for the 333 and reflections in a pair of measurements. The main merits of this method are: (1) The necessary scaling is easily carried out by use of the intensity of even reflections observed simultaneously; (2) Unwanted fluorescence contributions can generally be separated. These make the conclusion more reliable. It was thus established that the less shiny surface is the Ga side when a 111 plate of GaP is treated by an etchant (HF:HNO 3 = 5:1).